title: Gibberellin production by newly isolated strain Leifsonia soli SE134 and its potential to promote plant growth.
abstract: Very few plant growth-promoting rhizobacteria (PGPR) are known to produce gibberellins (GAs). The current study aimed to isolate a phytohormone-producing PGP rhizobacterium from soil and assess its potential to enhance plant growth. The newly isolated bacterium was identified as Leifsonia soli sp. SE134 on the basis of partial 16S ribosomal RNA gene sequence. Application of L. soli culture filtrate significantly increased the biomass, hypocotyl, and root lengths of cucumber seeds as compared with non-inoculated sole medium and distilled water treated controls. Furthermore, the PGPR culture was applied to the GA-deficient mutant rice cultivar Waito-C. Treatment with L. soli SE134 significantly increased the growth of Waito-C rice seedlings as compared with controls. Upon chromatographic analysis of L. soli culture, we isolated, detected and quantified different GAs; namely, GA1 (0.61 ± 0.15), GA4 (1.58 ± 0.26), GA7 (0.54 ± 0.18), GA8 (0.98 ± 0.15), GA9 (0.45 ± 0.17), GA12 (0.64 ± 0.21), GA19 (0.18 ± 0.09), GA20 (0.78 ± 0.15), GA24 (0.38 ± 0.09), GA34 (0.35 ± 0.10), and GA53 (0.17 ± 0.05). Plant growth promotion in cucumber, tomato, and young radish plants further evidenced the potential of this strain as a PGP bacterium. The results suggest that GA secretion by L. soli SE134 might prove advantageous for its ameliorative role in crop growth. These findings can be extended for improving the productivity of different crops under diverse environmental conditions.
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Sang-Mo
authors.initials: SM
authors.lastname: Kang
authors.forename: Abdul Latif
authors.initials: AL
authors.lastname: Khan
authors.forename: Young-Hyun
authors.initials: YH
authors.lastname: You
authors.forename: Jong-Guk
authors.initials: JG
authors.lastname: Kim
authors.forename: Muhammad
authors.initials: M
authors.lastname: Kamran
authors.forename: In-Jung
authors.initials: IJ
authors.lastname: Lee
mesh_terms: D000192:Actinomycetales / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D018533:Biomass; D018553:Cucumis sativus / Q000187:drug effects / Q000254:growth & development; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005875:Gibberellins / Q000378:metabolism*; D018546:Hypocotyl / Q000187:drug effects / Q000254:growth & development; D018551:Solanum lycopersicum / Q000187:drug effects / Q000254:growth & development; D008969:Molecular Sequence Data; D012275:Oryza / Q000187:drug effects / Q000254:growth & development; D063245:Plant Development / Q000187:drug effects*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D031224:Raphanus / Q000187:drug effects / Q000254:growth & development; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005875:Gibberellins; D012336:RNA, Ribosomal, 16S